Abstract
Overexposure to ultraviolet (UV) radiation is a threat to human health. It can cause skin cancer and cataracts. Human-made ozone-depleting substances (ODSs) reduce the ozone concentration in the Earth's stratosphere, which acts as a protective shield from UV radiation. To protect and restore the ozone layer, the Montreal Protocol on Substances that Deplete the Ozone Layer was enacted in 1987 to phase out the production and consumption of certain ODSs and was later amended and adjusted to significantly strengthen its requirements. The United States Environmental Protection Agency (EPA) uses its Atmospheric and Health Effects Framework (AHEF) model to assess the adverse human health effects associated with stratospheric ozone depletion and the U.S. health benefits from the global implementation of the Montreal Protocol. Comparing the Montreal Protocol as amended and adjusted with a scenario of no controls on ODSs showed the prevention of an estimated 443 million cases of skin cancer and 63 million cataract cases for people born in the United States between 1890 and 2100. In addition, 2.3 million skin cancer deaths are avoided. Compared with the original 1987 Montreal Protocol, strengthening the Montreal Protocol, through its subsequent amendments and adjustments, resulted in an estimated 230 million fewer skin cancer cases, 1.3 million fewer skin cancer deaths, and 33 million fewer cataract cases.